This invention relates to electric capacitors. It further relates to all-plastic electric capacitors. In a specific embodiment, the invention relates to electric capacitors made from a doped film of poly(phenylene sulfide). In a further embodiment the invention relates to a method of manufacturing an all-plastic capacitor.
Capacitors are electrical devices for storing electrical charge. They are composed of two electrically-conductive plates separated by an insulating material or dielectric. The conductive plates are generally metal layers which are applied as a foil or by vacuum-metallization. Depending upon the type of capacitor, the sandwiched layer is an insulator such as mica, ceramic, polypropylene, polystyrene, or other insulating plastics.
The capacitance of such a capacitor with dielectric area A and uniform thickness t is proportional to A/t. In order to achieve the high capacitance required in some applications, t is generally made as small as possible consistant with retaining sufficient dielectric breakdown strength, and the effective area is increased, which may necessitate rolling or stacking to achieve a convenient package size and shape. The thickness of the metal layers must be sufficient to provide low electrical resistance to the charging and discharging processes.
The process of preparing the conductive/insulating laminate which makes up the capacitor is a multistep operation. For reasons of economy and efficiency, it would be desirable to simplify the procedure for making capacitors and to minimize the amount of metallic material present in the capacitor.
It is therefore an object of the present invention to prepare a capacitor comprising electrically-conductive poly(arylene sulfide). It is a further object of one embodiment of the present invention to prepare an all-plastic capacitor. It is a further object of one embodiment to prepare a capacitor in which the conductive layers and the insulating layer are produced from a single sheet of poly(arylene sulfide).